Field of the Invention
The present invention relates to a silicon-based, broadband waveguide-integrated electro-optical switch for performing optical switching. More particularly, the present invention relates to an electro-optical switch for optically coupling and decoupling silicon-based waveguides.
Background of the Related Art
The demand for higher data communication capabilities continues to rise, spanning from long haul-down to board, and even the chip level [1]. Accelerating factors beyond developments in software applications are demands for higher data capabilities in hardware implementation. However, physical limitations such as power and thermal budget constraints appose these demands restricted by technology densification as seen in multicore technology and simple I/O capacity [2]. The latter imposes restrictions on the electronic chips, known as ‘dark silicon’ [3]. With the bosonic nature of photons lacking a photon-photon force, data parallelism is fundamental in optics and is routinely utilized in optical data communication such as wavelength division multiplexing (WDM) [4].
With the success of long-haul optical networks, optical interconnects at the board, and even at the chip-level, have become of interest in order to mitigate the processing-to-communication gap [5]. However, the majority of optical network-on-chip (NoC) routers perform their role not exclusively in the photonic domain but often in capacitive-limiting electronics. The later also requires an overhead-heavy optic-electric-optic (O-E-O) conversion. On the other hand, one can perform routing entirely in the electronics. Yet, the known performance bottlenecks of electronic devices, namely mainly delay and power dissipation, and clamping performance.
Turning to optical routing, on the other hand, is in itself inefficient given the current photonics technology due to the low light-matter interaction (LMI), and weak electro-optic modulation in silicon [6]. While photonic routers based on microring resonators have been proposed [7] and demonstrated [8], the high sensitivity (i.e. spectral and amplitude) require dynamic tunability which is both power hungry and relatively slow if high Q-factor rings are used. Hence taken together, optical routing is a) technologically cumbersome, b) latency- and energy-prone mainly due to O-E-O conversion, and c) suffers from high energy overhead due to signal error correction at the detectors TIA and laser stages, and from thermal tuning in rings-based routers [9-13].